Democritus

Democritus (460 BC-370 BC) was a Presocratic Greek philosopher who notably formulated an atomic theory of the universe.

Biography
Democritus was born in Abdera, Thrace in 460 BC, and Leucippus was his mentor. Their speculation on atoms, taken from Leucippus, bore a passing and partial resemblance to the 19th-century understanding of an atomic structure that led to Democritus later being considered more of a scientist than a philosopher. Democritus was largely ignored in ancient Athens, and he was disliked so much by Plato that Plato wanted all of Democritus' books burned. None of Democritus' writings survived, with only fragments being known from his vast body of work.